Stoker



March 3o, 1937.

F. w. voDoz STOKER Filed March 14, 1932 1l Sheets-Sheet l March 30, 1937. F. W. voDoz STOKER Filed March 14, 1932 11 Sheets-Sheet 2 March 30, 1937. F. w. -VODZ STOKER Filed March 14,` 1952 11 sheets-smet 3 W a l. 0 M w f /5 WM W am# 'J4 Z Heier/'66M J MW March 30, 1937. A F. w.`voDoz STOKER Filed March 14, 1932 11 sheets-sheet 4v March'30, 1937.

STOKERv Filed March 14, 1932 11 Sheets-Sheet 5 l Mrch 30, 1937. F. voDoz STOKER 1l Sheets-Sheet Filed March 14, 1932 March 30, 1937.

F. W.l vonoz: 2,075,149

sToKER Y Filed March 14, 1932 11 Sheets-Sheet-'B mnh-30,1937.' A F, W, VODOZ 2,075,149-

S TOKER Filed March 14, 1.932 11 sheets-sheet 9 l l 153 l l 'March 3o, 1937.l F. wyobz sToKER Filed March 14, 1932 11 Sheets-Sheet 10.

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l sToKER Filed Maren 11.1, 1952 11 sheets-sheet 11 Patented Mar. 30, 1937 UNITED vs'rirri-:s

PATENT oFFlcE This invention relates tor-improvements inf'automatic stoking devices for furnaces and the like, and more particularly to the type of stoker having means responsiveto variations in the volume of fuel in the fire-box for automatically adding new fuel and for 'shaking down the ilre whenA necessary. l

More specically, my present invention relates to the overfeed volume-responsive type of stoker 1o such as broadly disclosed in my prior applications bearing Serial No. 318,662 filed November 12,

1928, Patent No. 1,863,677 and Serial No. 447,154

nled April 25, 1930, but includes simplified and improved control, feeding and ash-shaking mechanism. A Other and more detailed features of improvement will appear from time to time from the following description.

The invention may best be understood by reference to the accompanying drawings, in which Figure 1 is a side view of a furnace of the ordinary household type to which my invention has been applied as an attachment, but with parts of th support and shaker means broken away.

Figure 2 is an enlarged fragmentarydetail view of the device shown in Figure l, but with parts broken away and shown in section to4 show details of the operating4 mechanism and with the feeding device in retracted or inoperative position. K

Figure 3 is a rear end view of the device shown in Figure 1 looking toward the furnace and drawn to the same scale as Figure 1.

Figure 4 is an enlarged transverse section taken on line 4-4 of Figure 2. 1

Figure 5 is a sectional plan view taken on a line extending in a generally horizontal direction above the feeding ram, but with parts broken away to show the portionsof the operating mechanism.

Figure 6 is an enlarged detail view taken generally on line 6--6 'of Figure 5 showing details of the control mechanism with the feeding shovel and ram in their retractedor inoperative position.4

Figure 7 is a view somewhat similar to Figure 6, but showing the feeding shovel and ram in their forward'most or discharging position.

Figure 8 is an enlarged detail view ofthe control box showing the electric switches mounted therein.

Figure 9 is an electric'wiring diagram showing the arrangement of the control switches and circuit connections with the feeding motor.

Figures 10. 11. 12, and 13 are diasrammatic erating plants or the like.

views of the controlfmechanism shown in detail in Figure 8 indicating the positions of the respective parts dining several stages of the cycle vof feeding operation of the apparatus, as willl more fully be described. 5 Figure 14 is a view of a modied form of control mechanism which may be used in place -of the control mechanism shown in detail in Fig- ,ure 8.

Figures 15 and'16 are diagrammatic views il- 1o lustrating certain operating positions of the parts of the modified form of control mechanism shown in Figure 14 during certain stages of the feeding operation.

Figure 17 is a detail view of a modified form of l5 showing the starting switch carrier and auto- 25V matic time limit switch.

Figure 25 is a diagrammatic view showing a -modied form of feeding mechanism including means co-operating between the shovel and the contact controlarm for raising the latter while the shovel is moved into fuel discharging position over the fire bed.

Figure 26 is a detail of the shaker rod adjusting device.

Referring now to details of the device shown 35 in the drawings and illustrating one form in which my invention may be embodied, Il) indicates a hot air furnace of the ordinary household type including a nre box I I, grate I2 and ash pit I3, all of the usual construction.` 40

In the form shown, the grate I2 is of the revolving mushroom type supported at the center on an upright ilnger I2 carried on a cross support I2band normally shaken down by oscillating the grate through a suitable rod I4. It will 45 be understood, however, that this specic type of furnace is shown merely as a means of illustrating my invention, andv that my improved device can, with slight modlflcationsfbe applied to a Wide variety of coal or coke burning furnaces 50 adapted either for domestic use or in steam gen- As shown in the drawings, my improved stoking device is constructed as an attachment to bev applied as a unit to a. domestic furnace, but it 55 will be manifest that it can be built as an integral unit, if so desired.

When constructed as an attachment, I provide a standard or base indicated generally at 5 I1, made up of a plurality of horizontally extending frame members I3, I9, and 25, said frame members projecting at various angles `from a center hub 2| and` having upright supporting legs I8, I 3l, and 2lin at their outer ends, re-

m spectively.

In the form shown, the horizontal frame members I8 and 2Il are in substantial alignment with each other and are positioned adjacent and across the front of the furnace, while the frame member I3 is preferably pivotally connected to the central hub 2I by means of U-bolt 22 as shown in Figures l and 2 so as. to permit the rearwardly extending frame member I5 with its leg J3* to be swung in a horizontal plane and adjusted at several angles relative to the furnace, and thus 'accommodate itself to obstructions such as supporting posts and the like, which may be positioned adjacent the front of the furnace.

Supported on the base I1 through and above the hub portion 2| is a pivot pin 23 upon which is carried a main supporting bracket 24. 'I'his supporting bracket is connected to and forms a part of the main casing 25 of the stoking mechanism, the arrangement being such that the entire stoking mechanism .l is supported on the bracket 24 so as to be swung as a unit on the upright pivot pin 23. As will be seen from Figures 3 and 5, the hub portion 2|. and pivot pin 23 of the base frame I1 are disposed at one side of the fuel supply opening or ilre door I5, while the stoking mechanism is mounted on the supv porting bracket 24 so as to be in registering engagement with said furnace opening when in operative position.

In Figure 5 the dotted lines A and B indicate the position of the feeding mechanism and supporting bracket, respectively, when the latter are' swung as a unit on the pivot pin 23 so as to be fully removed from the furnace opening and arranged in a position at substantially right angles to the latter.

The front or inner end of the casing 25 has an elongated portion that extends in fitting engagement within the fire door opening I5 and consists of a flanged upper plate 23h, forwardly projecting side plates 25, 25 and bottom plate 29, as is best shown in Figure 2. vWhen in closed position against said re door, the portions of the casing are sealed by means of a frame 45. Said sealing frame consists of a longitudinal flange 4II'L and a laterally extending iiange 43h. 'I'he entire frame is adjustable longitudinally of the front end of the casing by means gof set screws 40, 4Il which extend through the longitudinalilange 40'i toengage the adjacent sides of the casing 25. The laterally extending iianges 40b may thus be adjusted so asto ilt closely againstI the outer margin of the ilre door opening I5 when the'apparatus is in closed position. as shown in Figure 2. Suitable packing means such as cement may be inserted between the frame 45 and the sides of the casing as indicated at 45S.

Referring now to details, of construction of the stoking mechanism, the main casing 25 has mounted thereon a hopper 25 mounted on a 7o downwardly extending discharge spout or passageway 21 opening into the forward end of said casing, that is to say, the end nearest the furnace. In the form shown, said discharge spout 21 is'integral with the casing as shown in Figure 75 4, and the hopper is detachably secured thereto.

A plurality of lugs 25* fit over a bead 25*l on the outer margins of the spout, and a wedge pin 29 is driven between each of said lugs and head, as clearly shown in Figures 1 and 2.

The hopper 26 and the connecting portions of the discharge spout 21 of the main casing are preferably formed with corners having illlets of s-zbstantial radius as indicated at 25, 25h on Figure 5, which is found to be particularly advantageous in insuring free downward flow of the fuel into the casing.

Mounted'within the main casing 25 and slidable longitudinally thereof is a hollow shovel member 35 consisting of side walls 32, 32, a rear wall 3|, a top wall 33 and a bottom wall 34. Said top wall 33 extends over the rear portion of the shovel to a point approximately midway the length of the latter, as best shown in Figure 2, while the bottom wall begins at a point approximately opposite the front margin of the top wall 33 and 'extends forwardly to the front edge of the shovel.;

As will be seen from Figure 2, the top wall- 33 of the shovel is retracted beyond the discharge opening 21 of the hopper when the shovel is in its rermost position. 'Ihe entire shovel, however, is slidable longitudinally within the casing 25 so as to be moved forwardly toward the ilre box, with the bottom plate 34 of said shovel sliding along the bottom plate 23- and the top wall 33 sliding beneath inwardly extending guides 21, 21" formed along opposite sides of the upright plates 15, 15.

Telescopically mounted within the shovel is a ram 35 'consisting of an upright ejector plate 35, side plates 31, 31 and a top plate 35. The top and side plates are strengthened by an intermediate transverse web 35 and a similar web 45 at the rear end of said ram. 'Ihe central portion of the ram is hollow except for a longitudinally extending rack bar 4I which is attached adjacent the bottom edge of the ejector plate 35 by suitable means such as bolt 4I* and extended rearwardly beyond the main body of the ram and through the rear end wall 3I of the shovel. mounted on the rear of said shovel end wall so as to enclose the projecting rear end of the rack bar 4I when it extends beyond said end wall.

The power drive means for the shovel and ram consists of a reversible electric motor "suitably mounted on the casing 25, and in the form shown in Figures l to 7 being suspended beneath the under side of said casing adjacent the outer end thereof. Said motor has a transversely' disposed armature shaft 45 and pulley 41 about which a belt 4I is trained to engage with a pulley 43 on transverse shaft 55. The shaft Il has bearing in a gear case 5I also suspended beneath the main casing 25 and connected thereto by suitable means such as bolts 5I, 5I. A worm 52 is ilxed on the shaft 5l within the casing 5I, said worm engaging a worm wheel 53 on an upright shaft 54 having suitable bearing within said casing as by means of anti-friction roller bearings 54 and 54 at the upper and lower ends of v said casing, as best shown in Figure 2. The

shaft 50 may be provided with a squared socket 50* at one end, so as to accommodate a detachable hand crank 50" for manual operation of the mechanism, in case of emergency, al indicated in dotted'lines in Figures 3 and 4. n

For convenience in assembly and accessibility, the upper anti-friction roller bearing 54* is carried in a cover plate 55 detachably mounted on A hollow guard member 42 isv the upper end of the casing 5 I. At the upper end of the upright shaft 54 above the cover plate 55 is fixed a pinion 56 which has toothed engagementl with .the rack 4| forming a part of the ram 35 as aforesaid. A guide roller 51 is mounted on an upright stud 58, and engages the rear side of the rack bar opposite the pinion 56.

Means are provided for moving the shovel and ram forwardly by power to feed the fuel and spread it on top of the fire, and returning said shovel and ram by reversing the motor 45.v In the formv shown herein, the ram and shovel are connected for simultaneous movement during a part of their forward stroke, until the shovel is moved inwardly to a position where the fuel is discharged over the center of the firebed, whereupon further movement of the shovel ceases but movement of the ram continues so as to eject the charge offuel within the forward end of the shovel upon the nre. This connecting mechanism also includes means for automatically holding the shovel in its forward position until the ram has been returned to its initial position relative to said shovel, whereupon the ram picks up weights 60c and 6l, respectively, so as to tend toY swing their respective detentsirffupward position.

A projecting bracket 63 issupported at the rear end of the ram 35, said bracket having a forwardly facing shoulder 68 which is normally adapted to have engagement with the detent 60b of the lower pawl 60. When so engaged it will be observed that the pawl 60 is held in forwardly inclined position as clearly shown in Figure 2..

The bracket 63 also has a rearwardly facing shoulder 65 adapted normally to engage the counterweight 6lc of the upper pawl 6I so as to hold said pawl in a generally forwardly inclined position substantially parallel to the lower pawl 60 as also shown in Figure 2.

'Ihe engagement between pawl 60 and the bracket 63 carried by the ram is such that forward movement of the ram produced through rotation of the pinion 56 on rack l causes the shovel to be carried forward with the ram until the lower pawl is tripped by a stop 66 which is fixed to the casing 25, and projects upwardly into the path of movement of the counterweight 60 of said pawl.

Thus when the .pawl 60 is carried forwardly so as to engage the counterweight 60c with the stop 66, the detent 60b is swung downwardly out of engagement with the shoulder 64, thereby unlocking the driving connectionv between the ram 35 and the shovel 30, and permitting the ram to continue its forward movement while the shovel remains stationary. Just before this-unlocking action occurs, the uppenfend of detent 6|.b carried by the upper pawl 6l passes beneath the bearing plate 2lb on the main casing, and assumes a. position forwardly of upright shoulder 61. This locks the shovel against rearward movement relative to the casing so that during the initial retractive movement of the ram the shovel remains stationary until the pawl 6I becomes unlocked by engagement of the counterbalance 6Ic by upright shoulder 65 carried by the bracket 63 at the rear end of said ram.

It will be noted that the topplate 33 of the shovel forms in effect a partial closure of fuel valve as it is moved forwardly beneath the discharge passage of the fuel hopper 26. Moreover, when the ram is moved forwardly of said shovel top plate, the top plate 38 of said ram forms an extension of said shovel top plate, and also keeps particles of fuel from falling behind the upright plate 36 of-said ram and fouling the operation of the mechanism.

The co-operative relation of the parts just described with respect to the control devices for automatically starting the motor and reversing its direction of rotation at the extreme forward limit of movement of the ram, will hereinafter more fully appear.

Immediately forward of the bearing plate 21h I provide a chamber 59, opening downwardly upon the top plate 33 of the shovel. This chamber is filled with a suitable packing material 598' such as asbestos fibre, which serves to wipe fuel dust from the upper surface of the shovel as it passes back and forth in its feeding strokes.

In orderto protect the unburned fuel disposed in the shovel and hopper from excessive heat before itis fed forwardly into the re box, I provide a plurality of baille means or doors adjacent the front end of lthe main casing 25 where it extends into the fire door. In the forni shown, said baffle means comprisean outer door 68 hinged o-n transverse pin 69 supported between the side plates 28, 28 just within the fire door opening l5. door is adapted to fit closely between the side plates 28, 28 and when in closed position is in,- clined at a forwardly extending angle so as to engage the Vforward edge of the bottom plate 29 as clearly showny in Figures 2 and 5. A second door 10 is also hinged on the pin 69, this second door being slightly narrower than the outer door 68 and arranged so as to depend between the side walls 32, 32 of the shovel 30 when the latter is in retracted position, as shown in Figure- 2. The door 'i0 is relatively heavy and massive so as to tend to be swung downwardly by gravity against the fuel deposited within the shovel, so as to form an open space between the said shovel and .the outer door 68 as clearly shown in Figure 2.

-In connection with the discharge passage between the side plates 28, 28, I also find it desirable to provide a flanged Web 12 projecting downwardly from the upper plate Zb of the casing 25 which projects into the fire door l5, said web extending across the upper part of the space between said plate and the upper margin of the shovel and arching down to the shovel guides 21, 22a, as clearly shown in Figure 4. This web limits the size of the fuel discharge opening, but with substantial clearance above the shovel, thereby restricting the amount of fuel that can be carried forward on the shovel, but eliminating shearing of the fuel at the top of the shovel. After the fuel has passed the web 12, much of the lateral pressure is relieved so that it is passed forwardly through the baille plates 68 and 10 without danger of jamming the latter.

The means for. automatically controlling the operation of the feeding mechanism is of the same general type as disclosed in myprior applications bearing Serial No. 318,662 led November 12, 1928, Patent No. 1,863,677 and Serial No. 447,154 filed April 25, 1930, Patent No. 1,984,852 wherein a oating control member is mounted so as to extend above and in contact withv the Said` l said control member.

In the improved form of control mechanism shown herein, the weighted contact member 'Ii is detachably mounted in the re door opening l" independently of the other parts ofI the mechal l5 nism. Said contact member consists of 'a piece of ilre brick 'I6 which depends in upright position from an ann 11 extending into the iire box. so that the lower end of the fire brick may rest upon the iire preferably adjacent the center thereof, but to one side of the path of travel of the shovel 30. (See Figs. 1, 5, and 6.) The arm 11 is rigidly connected to a support 1l by bolts lll, 18|. Said support is hinged on pin 'Il having bearing at opposite ends in a bracket Il which 'is detachably mounted within and at one side of the door opening Il. Ihe bracket Il consists of a pair of laterally spaced plates Ii, 8| extending in vertical position and spanning the pivoted end of the swinging support 1l. The upper ends of '30 the bifurcated pistes u, u meet in s-pair or bosses 82, I2 which have set screws 02, l2* extending upwardly 'therethrough for mentent with .the -roof of the iire door opening Il. The lower ends of the plat 8| are Joined together in a similar boss 83 having'a set screw I3* extending therethrough'for engagement with the lower wall ofthe ilre door opening Il. This construction isbestshowninFlguresSand 8. Thearrangement is such that the floating control 40 member II with its pivotal supporting bracket Il maybe detachably mounted in the proper position within the ilre door opening with adjustments for variations in sizes of nre doors, andthe main casing 2i can be swung away from the iire door '45, opening Awithout disturbing the control mem- The supporting member 'Il is provided with a laterally projecting lug I9 which engages one of the .upright .plates 8| to vlimit the downward swinging of the control arm 1.1, thereby facilitating the starting of anew iire.

The supporting member 1l of the floating arm is provided with an outwardlyprojecting spur II Awhich is adapted to engage a shoe carried on theforward end of acontrolrod l1 whichextends4 a through theadiacent flanged portion of the sealing frame 4l and into the controller'casing 8l formedatonesideofthe maincasing 2l.- 'v

The switch mechanism for automatically con-V co trolling the starting, reversing and Stopping Voi? the motor which drives thei'eeding shovell and xamtlisforthemostpartlocatedwithinthis' Detailsof one formofthis I controller casing Il.

mechanism are shown in Figure 8, the wiring diagram of the said mechanism is shown in Figure 9, and working diagrams of the 4operating positions of said mechanism are shown in Figures 10 to 13,l both inclusive.

The several circuit connections are controlled through a series of switches of the well known mercury tube gravity type, mounted within the casing 88. In the form shown herein, each of said mercury tube switches is of the usual form,

consisting .ofnan evacuated tube having spaced '-75 terminals at one end thereof. and a small amount of iiuid mercin'y in said tube arranged to close the circuit between said terminals when the tube is tilted with the terminal end downwardly and the mercury ilows by gravity to contact both terminals. The circuit connections for these switches are shown in Flgm'e 9, as follows:

The main power supply lines for the motor 45 are indicated at and 9|. One side of saidmotor is connected to one of the power lines, as for instance line- 9| by conductor 92.` Conductor l2 includes an automatic time limit switch IIB as will hereinafter be described. Twoconductors 93" and l are connected to the motor for driving the latter in reverse directions. Theconi ductor 93* leads to one terminal at the end of a mercury tube switch Il, and the conductor Il leads to one terminal at the end of a mercury tube switch M. The two tube switches 93 and M are mounted substantially parallel with each other on a common rocking carrier l5 hut the terminal ends of said mercury tubes are arranged in op y positelyv extending directions on said can'ier so,

that'when one switch isrocked into the proper ,l

position to close the circuit at the terminal end thereof the other switch will be rocked into the opposite, or open position, and viceversa. The

second terminals of the switches I3 and 14,' re.-

spectively, are connected by conductors l!" and u* to a common conductor 0I which has one branch 9|* leading to one terminal of a mercury switch Il and another branch Il leading to one terminal of a mercury switch I8. .'lme second terminal of switch 91 is connected through conductors 99 and |00 to the main supply line l0, while the second terminal of mercury switch I8 is likewise connected to the last named power supply line through conductors IIII and fIII. It

will thus be seen thatthe mercury switches l'l and 98 are arranged to be in parallel `with each other when closed. i

'Ihe mercury switch Il is mounted on rocking carrier Il* co-operatively connected with the carrier II on which the reversing switches 93 and 'I4 are mounted,- and serves to can-y the operating circuit after the feeding mechanism has beg1m` its `forward stroke and the starting switch 88 has been rocked into open position. as will hereinafter more fully appear.. The switch I1 is, for convenience. hereinafter referred to as the carry-over switch.

'I'he switch 9| is mounted on arocking carrier -98 and is mechanically controlled to start the forward feeding movement, as will hereinafter appear. Said switch is, for-convenience. hereinafter referred fn as the starting switch.

,In the form shown, the cariers 0i and il* areV l mechanically connected by means of a snap switching device so that when the lower Ycarrier Lis rocked in one direction, the upper carrier will be automatically rocked in the other direction, and vice versa. This mechanism is shown in detail .in Figures 20, 21,*and 22.

'I'he lower' carrier 95* forms the actuating con'- nection for the mechanism, being operated by vtrip lever H5 at certain periods of the operating cycle, as will hereinafter more fully appear. Said lower carrier is pivotally mounted on a pin |24 xed cna base plate I 25. n Said carrier has a lateral extension |28 to which is pivotally connected` an upwardly extending link |21. Said link has a roller |28 at its upper end adapted to have engagement with one side of the upper carrier which is pivotally mounted on pin I2 9. The side of said upper c arrier is formed with a projection |3|l and adiacent inclined surfaces |3| 'and |32 above and below said projection as clearly shown in these figures. is urged by tension against one or the other of these coacting surfaces by means of a spring |218 5 vconnected to the link |21.

in Figure 22, the roller |28 engages the lower in-A clined surface |32 and urges the upper carrier l5 in a clockwise direction with the upper shoulder |34 engaged againstl the stop |33. As the lower carrier 95 is shifted toward the left, the position of the upper carrier is unchanged, as the roller moves outwardly' against the tension of the springalong the under inclined surface |32, until a point is reached adjacent the extreme left-hand position of the carrier 955 when the roller passes over the projection |30 (see Fig. 20). At the instant this occurs, the upper carrier 95 is quickly rocked in a counter-clockwise direction, due to the pressure of the roller on the upper inclined surface |3'I, thereby shifting the mercury tubes 93 and 94 into reversing position, as shown in Figure 21. When, at a later period in the cycle of operation, the lower carrier 95Il is shifted toward the right, the roller |28 moves downwardly along the upper inclined surfaceuntil it passes over the projection |30, whereupon the upper carrier .95 is swung back in a clockwise direction. It will be seen from the following description that the shifting of the reversing mercury switch vtubes is accomplished instantaneously with a snap action at the extreme forward and rearward positions of the lower carrier 95 through action 40 of the trip lever ||5 connected thereto.

Referring now to Figure 8, 'the parts are shown with the shovel and ram at rest and all parts in non-operative position. The control rod 81 is pushed toward the furnace because control arm 15 is supported by a su'fhcient charge of fuel in the fire box. In this position both the starting switch 98 and the carrying switch 91 are held in open position so that no current is supplied to the motor.

The control rod 81 has a depending nger |05 thereon which is adapted to engage a projecting portion |06 of the starting switch carrier 98a. The carrier 98B is made up of two parts, the upper part |08 being pivoted to the lower part |06 by pvot pin |01, while the lower part is in turn pivoted to the switch panel 88a by pivot pin |09. Under normal operating conditions the upper and lower parts, of the carrier are held in xed relationship so as to rock as a unit on the pivot pin |09. An automatic time limit switch to be later described is provided so as to cut oil the operating current automatically after the feeding mechanism has been in operation for an excessive period of time. o5 In the usual or normal operation of the starting switch, the control rod 81 is responsive to movements of the control arm 11, and as the latter drops with the fire bed, the depending finger |05 moves into engagement with the lower part |08 of the starting switch carrier, and 'slowly rocks saidvcarrier bodily on its pivot |09 until a position is reached as shown in Figure 10, when the starting switch 98 becomes closed. Referring to the circuit connections in Figure 9, it will be '75 seen that current is then supplied from power The roller |28 line through conductors |00 and |0|, starting switch 98, conductors 96h and 94", mercury switch 94, conductor 94a to the motor 45, and thence through,A conductor 92, time limit switch ||0 l,to the other power line 9|. This circuit connection starts the motor in a direction to move the shovel 30 and ram 35 toward the fire box as indicated by the arrow in Figure 10. As will be seen from this gure, both the reverse switch 93 and the carry-over switch 91 are in open position, the carriers 95 and 95 having been forced into 'this position during the nal retractive movement of the ram 35 by means of a trip lever H5, the lower end of which is engaged by a stop H6 carried adjacent the inner end of rack 4|, while the opposite end oi said trip lever is engaged within a loop ||1 formedin'the lower end of the carrier 95la (see also Figure 8). A tension spring ||8 on plunger ||9 engages a shoulder |20 xed on the main casing 25 and tends to urge -said plunger against the trip lever I5. Saidspring ||8 is arranged to be placed'under compression during the time that the stop ||6 moves to its rearwardmost position, as shown in Figure 10. v

As soon as the motor starts the ram 35 forwardly, the stop ||6 is carried therewith so as to permit the storedenergy in spring ||8 to rock the upper end of trip lever ||5 to an intermediate position shown in Figure 11, thus rocking the lower carrier 95e rearwardly a suiiicient distance to throw the carry-over switch 91 into closed position. Said carry-over switch .beingl in parallel withthe starting switch as previously described, the operating current may then iiow through the carry-over switch and its associated conductors for operating the motor through an entire cycle comprising the forward and rearward strokes of the ram and shovel.

The carry-over switch serves the important function of continuing the circuit connections through the motor during that period of time when the shovel 30 approaches and leaves its extreme position of inward or feeding movement as indicated in Figure 12. At this point in the cycle, an upright lug |22 on the rear end of said shovel engages the rear end of control rod 81 so as to push said rod forwardly and bodily lift the control arm 15 from the re so as to permit the fuel to be fed upon the top of the re without interference from said control arm. In this position it will be seen thatthe finger |05 carried by control rod 81 is moved out of engagement with the starting switch carrier 98a so that said switch is swung into open position during the brief period that the control arm 15 is elevated above the re in the manner described.

As the ram approaches its extreme forward- A most position as shown in Figure 12, a stop |23 on the rear end of the rack 4| comes into engagement with the trip lever ||5 and rocks the carrier 95a to its extreme rearward position as shown in Figure 13. By reason of the automatic snap switch connection between the upper and lower carriers previously described, the upper carrier 95 is rocked by a quick action into a reversely inclined position, 'as shown in Figure 21. This rocking movement of the upper carrier 95 causes the forward operating switch 94 to be opened while the reverse switch 93 is 'simultaneously closed. It may be observed that during this .movement of the lower carrier 95m the carry-over With the switches 93 and 94 in reverseposi-` tion shown in Figure 13, reference to the wiring diagram of Figure 9 shows that the circuit connections to the motor will be such as to drive the latter in reverse direction through the reverse switch 93 and its associated conductors 93' and 93h instead of through the switch 94 and its associated conductors 94* and 94".` 'By this time the ram 35 will have discharged the entire charge of fuel from the shovel 30 and said ram will be moved rearwardly to its initial starting position as shown in Figure 8.

As the ram approaches its rearwardmost position shown in Figure 10, the stop H6 on rack 4| engages the trip lever ||5 and the latter swings the lower carrier 95 forwardly so as to rock thel carry-over switch 91 into open position. At the same instant the upper carrier 95 is rocked to its forwardmost or starting position, as shown in Figure 8. Some time before this initial position has been reached, however, the lug |22 on shovel 30 has been moved rearwardly out of engagement with the control rod 8l, thus permitting the contact control arm I5 to resume its position on top of the ilre bed.

In the event that a sufficient amount of fuel has been deposited upon the re bed to bring it up to its normal height, the control arm will be supported and maintained on said bed, and a coil spring |30 which normally tends to urge the control rod 81 forwardly, will operate to move the lever IIIB out oi' engagement with the starting switch carrier has shown in Fig. 8. v'Ilius when the ram reaches its outermost or initial position as shown in Figure 8, and a sufficient 'charge of fuel has been added to the fire, the starting switchv 98 will be open so that the motor circuit will be broken at the instant the carry-over switch l1 is snapped into open position. A

It will be observed further, however, that in the event that the charge introduced during a single feeding cycle of the shovel and ram is insumcient to provide support for the control arm at a predey termined height as it is lowered into contacting position upon the top'of the replenished nre bed, the startingswitch 98 will remain closed at the end of the cycle, (although the carry-over switch 91 is open at this instant). Said starting switch will thereupon serve to continue the operation of the motor through as many cycles as are necessary to replenish the fuel to a point where the control lever I1 is supported at the proper height.

'I'he automatic time limit switch III is shown in detail inFigures 23 and 24 and consists of a carbon pack IIB* in series with the main operating circuit, as shown in Figure il.` Said carbon pack is mounted in an insulated casing HU", and is maintained under pressure of threaded cap I |l against a bi-metal strip Illib, secured tothe lower part Ill. The free end of said strip is normally arranged in the path of stop III depending from the upper part |08. A tension coll spring III is connected between an oil'set portion III* of part Ill and the upper part IBI of switch il, said spring being arranged to urge and normally hold the depending4 stop In against the strip Ill.

In the event that the main circuit connections from 9| through conductor I In", strip |06". carbon pack III* and conductor 92 have been closed for an excessive period of time, the heat generated in the carbon pack IIII is suillcient to bend the bi-metal strip I 08 out of engagement with the stop |08, thus permitting the upper part |08. and the starting switch 98 carried thereon to be rocked by the coil tension spring III into open position, thereby automatically shutting oil the operation between the operating circuit, regardless of the position of the control rod 8l and the lower part |06 of the carrier. Of course, as soon as the carbon pack is cooled again, the parts willresume their -normal operating positions.

It will be understood, of course, that the preceding description is mainly directed to the operation of the starting, carry-over and reverse switches for operating the motor, and no reference has been made to the co-operative connections between the ram and the shovel through the medium of the pawls and 6I. These co-operative connections, however, have been previously explained in connection with the detailed description of the shovel and ram, and their relative positions during the operation of the several switches will be understood by reference to Figures 10'to 13.

. In order to maintain a ilre bed of uniformicharacteristics with the automatically controlled fuel feeding mechanism above described, I ilnd that it is also important to provide means for automatically discharging the ashes from the bottom of the fire. Otherwise if the ashes were permitted to accumulate at the bottom of the re box, the depth of the ilre bed would be gradually diminished until the re is choked out. It is manifest, therefore, that in order to insure a continuously operating device, it is necessary to insure a periodical shaking down of the nre in timed relation with the addition of fuel to the top of the bed.

In the form shown, the grate I2 is arranged to be shaken down automatically eac'h time fuel is added to the ilre. For this purpose the shaking rod Il of the grate is connected by a laterally extending link MII to an upright shaking lever Ill suitably pivoted'on a bracket |42 and arranged in a convenient position, as usual, for shaking down the fire by hand. A detachable connecting rod |43 is provided between the lever III and a crank arm I fixed on the lower end of the upright shaft Il which also carries the driving pinion 56 for the feeding rack of the ram Il. 'Ihe connecting rod I is preferably provided Iil of the crank arm l, this adjusting means herein consisting of a bolt I having an enlarged end lub upon which the connecting rod I is pivoted.- A reduced portion 3 passes through ii.

serrated washer |434 and together washer is adjustable longit |44* and clamped to the shown in Figure 26.

with said of the slot The opposite end of the connecting rod lhasy With the construction just dcribed, it will be' seen that thegratewlllbeshakendowneachtime the feeding mechanism operates. The eii'ective stroke of the grate is adjustable by means of the slotted connection between connecting rod I andthecrankarm I,soastoeliminatesuhstan tially all of the ash each time the grate is shaken,

arm I by nut Ml, as-

and therefore` maintain .substantiaiiy uniform f characteristics of the lire.

Although the various parts of fthe operating and control mechanism have been described in detail, a brief rsum of the operation of the principal parts may be desirable to show the cocontrol, the automatic feeding andthe automatic shaking mechanism during a complete cycle of operation.

With the feeding and control mechanism in.

their idle or inoperative position shown in Figures 1, 2, and 8, the shovel 30 and ram 35 are in their outwardmost position so long as the contact member 16 or control arm 11 is maintained at a. predetermined height on the top of the fire bed.

As the fuel is consumed so as to permit the arm 1o to drop below this predetermined height,'the control rod 81 is pushed longitudinally so as to 'rock the starting switch 98 and initially close the operating circuit for the motor. The ram and shovel are then started inwardly toward the fire as shown in diagram in Figure I10, the shovel being connected by pawl 60 to the ram. When the ram has moved forw-ardly a short distance, the trip lever |I5 is swung on its pivot by tension of spring I I8 a sufficient distance to rock the carryover switch 91 into closed position, as shown in Figure 11.

Forward movement of the ram and shovel is continued until the pawl 60 moves into engagement with the stop 66. In Figure `6 the parts are shown with the shovel in dotted lines where the pawl 60 has almost reached the stop 66 and the forward end of the shovel has almost reached a position substantially over the center of the fire bed.

Just before theshovel is disengaged from the ram, projection |22 carried by said shovel engages the rear end of the control rod 81 so as to lift the control arm and contact member ,16 from the top of the fire bed. The shovel and control arm are maintained in this position by engagement of the upper pawl 6| with the shoulder 21b as shown in Figure 7. As the pawl 60 is released, further forward movement of the shovel ceases, but the ram is continued in its forward movement as indicated inFigure 12.

After the forward movement of the shovel has ceased and the control arm 11 is in raised position, as described, the forward movement -of the ram 35 continues so as to discharge the fuel from the shovel and spread it upon the top of the ilre, which it will -be understood is now unobstructed by the contact member. Theram is moved forwardly until stop |23 carried therewith engages the trip lever I I5 and through snap operation of the carrier 95a throws the reversing switches 93' and 90 into reverse position as shown in Figure 13.v

The ram is then moved rearwardly, picking up the shovel. Projection |22 on the latter is then moved from engagement with control rod 0I?v so as to release the control arm and contact member and permit the latter to drop upon the top of the newly-fed fuel. The shovel and ram are returned to their initial or starting position Where the reverse and carry-overA switches are thrown over` into the position indicated in Figure 8, whereupon the motor circuit is automatically opened to stop operation of the mechanism, provided, of course, suicient fuel has been added to support the contact member 16 at the proper height. If not, the starting switch 90 will again be closed to start another feeding cycle.4

During each feeding cycle, the shaking mechanism is operated from the same shaft 54 that operates the feeding ram.

It will be observed further that the spring |30 on control rod 81 is normally placed under compression, which is increased by the weight of the contact control arm 15 acting thereagainst. Consequently, when the feeding mechanism including the main casing 25 is -pivotally swung away from the front of the furnace fuel door, as indicated in dotted lines in Figure 5, the pressure on spring I 30 is relieved and the control rod is urged forwardly thereby so that finger |05 is moved a substantial distance from the starting switch 98'. In this manner danger of accidental starting oi the feeding mechanism is practically eliminated.

In the modified form of vswitch control mechanism shown in Figures 14, 15, and 16, the starting switch 98 and reversing switches 93, 94 with their circuit connections are arranged as inthe previously described mechanism, but the carry-over switch has been omitted. In its stead, an intermediate system of control levers is provided which are arranged to hold the starting switch in closed position during tlm entire feeding cycle. Said intermediate control system comprises a cam member |05a xed on the control rod 81 under forward compression of spring I30, a rocking contact lever |5I having a. roller |50 adapted to engage said cam member, and a horizontally disposed rod |52 connected to the lower end of the .starting switch lever |06 and suspended by link |53. The link |53 and the intermediate part of rocking lever |50 are each pivoted about a pin |59. A rearward extension I 55 of rod |52 is relatively exible in a vertical direction. The free end of the contact lever I5| opposite its roller |50 has a vertically disposed rod |56 depending therefrom, which extends through said extension and has a stop |565 at its lower end.

When in normal position, the extension |55 is.

adapted to engage and form a stop for the upper end of trip lever |I5a which corresponds to trip lever I5 of the previously described construction, but when said extension is flexed upwardly by the rod I56,`it moves above said trip lever and permits the latter to swing forwardly thereunder, as shown in Figure 15.

A tension spring |51 is connected between the free end of contact lever |5I and a fixed point |58 in a direction substantially in line with ,the pivot point |54 of said lever, when the latter is depressed by the cam, as shown in Figure v15. A second tension spring |59 connects the free end of lever I5| with the lower end of link |53.

The operation of the modiedI form of control mechanism above described is as follows:

Figure 14 shows the parts ih the'inoperativev position. with the starting switch open, and with spring |59 urging the extension |55 of rod |52 into engagement with one end of trip lever H53. The opposite end of the latter lever, however, is normally held from rearward movement by stop |I6 on rack 6I (see Fig. 15). As the fuel level lowers, the contact control arm 15 drops and pushes the control rod 01 inwardly, thereby forcing cam |05a against roller |50 and rocking contact lever |5| on its pivot |54. This pulls the rod |56 upwardly and fiexes the extension |55 so as to carry itl over the end of trip lever I |53. 'I'he rod |52 and extension |55 are thenfree to be shifted longitudinally under tension of spring |59, into the position shown in Figure 15, whereupon the starting switch 98 is rocked into closed position. The shovel and ram are then moved forwardly. The control arm 15 will be raised, and in doing so, the cam |05 will be pushed forwardly so as to relieve the lever- I5I, as shown n in Figure 16. This permits the flexible extension' |55 to resume its normal horizontal position, -so that it will be in the path of movement of lever IIS* when the latter is swung forwardly by pin ||6 atA the end of the return stroke of the ram.

The starting switch will thereupon be rocked into open position by the lever IIB, acting through extension |55 and rod |52 as described. VIn other respects, the control mechanism, including the reversing switches, operate in the same manner as the first described mechanism shown in Figure 8.

Figures 15, 16, and 17 also illustrates a modified form of pawl ISU for connecting the shovel and 10 ram. Instead `of being actuated'bygravity, it is controlled by a coil spring I 6I arranged to urge said pawl positively into locking'position excepting when engaged by the stop 68.

In Figure 25,.a modified construction is shown, in which the control arm 15 is raised automatically by the shovel 30, one side wall l of which is inclined along its front edge and engages a roller 15n mounted on said control arm. With this arrangement, the control arm is raised each time the shovel is advanced, to discharge fuel on the fire, and is permitted to drop again as the shovel recedes.

Referring to the modified construction for mounting the motor illustrated in Figures 18 and 19, the parts of the mechanism are the same 'as .those shown in Figures 1, 2, and 3, excepting for the position of the driving motor 4i* which e is transferred to a base -plate 45 forming part of the main supporting bracket 2l* adjacent upright pivot pin 23 on which the entire feeding mechanism is hinged. 'Ihe pulley 49* is in this form,

' transferred to the opposite end of the cross shaft 50, to be in line with the driving pinion 41. This construction may be preferred as somewhat more compact, and as a means of supporting the weight of the motor nearer its hinged support.

Although I have illustrated and described certain embodiments of my invention, it will be understood that I do not wish to be limited to the i0 exact construction shown and described, but that various changes and modifications may be made without departing from the spirit and scope of my invention.

I claim:

1. In a furnace, a fire box, a fuel opening therefor, fuel feeding means including a horizontally reciprocating shovel for discharging fuel into the fire box, power means for actuating said shovel, and control means for said power means vresponsive ,to variations in height of said fuel bed, including a vertically movable contact vmember projecting into said fire box and adapted to rest upon the top of the fire bed within said fire box, and means detachably supporting said .i5 contact member within s id fuel opening independent of said fuel feedng means and shovel,

the shovel being removable from the furnace without disturbing said contact member.

e 2. In a stoker and in combination with a fur- 60 nace, to fuel hopper, a casing supporting said hopper and forming a horizontally disposed fuel passage, said hopper having a vertically opening discharge passage communicating withsaid horizontal passage, a shovel reciprocably' movable along said casing under said vertical passage adapted in one position to receive fuel deposited by gravity therefrom, means for moving said shovel forwardly along said fuel passage, and for ejecting the fuel from said shovel at a point remote from said vertical discharge passage. said horizontal paage having a restricted portion disposed a substantial distance forwardly of said vertical passage but affording substantial clearance above said shovel whereby lumps of fuel projecting above the top of said shovel may pass `through said restricted opening during the forward feeding movement of said shovel.

3. In a stoker adapted to feed fuel to a furnace. a frame, a fuel hopper thereon having a vertically opening discharge passage, a reciprocating shovel having means for moving it under said discharge l passage adapted in retracted position to receive fuel deposited by gravity from said discharge pas-l sage and in advanced position to carry said fuel to a feeding position relative to said furnace, a ram telescopically mounted in said shovel, means for moving said ram relative to said shovel operative to eject fuel from said shovel when the latter is in its advanced position, said shovel having a top plate extending rearwardly therefrom adapted to form a closure for said discharge passage of the fuel hopper when said shovel is in its advanced position, and said ram also having a horizontal plate extending rearwardly therefrom and telescopically positioned beneath said first named horizontal plate to form a closure with the latter when said ram extends forward therebeyond.

4. In a stoker adapted to feed fuel to a furnace, a

fuel hopper, a casing supporting said hopper and forming a horizontally disposed fuel passage, said hopper having a vertically opening discharge passage communicating with said horizontal passage, a reciprocably movable shovel in said casing having a horizontal bottom plate, and a horizontal top plate adjacent its rear end, said shovel being adapted in retracted position to receive fuel in its forward end deposited by gravity from said hopper and adapted in forwardly extended position to project said horizontal top plate beneath said discharge passage of the fuel hopper-to form a closure thereunder, a ram telescopically mounted in said shovel, means for reciprocably moving said ram, means for connecting-said shovel with said ram to move with the latter during a portion of the travel of said ram. said ram having a horizonta'l plate extending rearwardly therefrom beneath said first named horizontal plate adapted to form an extended closure between said rst named plate and said ram when the latter is extended forwardly in said shovel.

5. In a stoker adapted to feed fuel to a furnace, a fuel hopper, a casing supporting said hopper and having a horizontally disposed fuel passage. said hopper having a vertically opening discharge passage communicating with said horizontal passage,

areciprocating shovel mounted in said horizontally disposed fuel passage and having a telescopically movable ram mounted therein for discharging fuel from said shovel, and a top plate carried by the rear end of said shovel adapted to cover -saidram when the latter is retracted in said shovel in loading position beneath said vertically opening discharge passage of the hopper, and means operated in timed relation with the forward feeding movement of said shovel causing extension of said ram within the latter to discharge fuel therefrom.

FREDERICK W. VODOZ. 

